Hi all, been a while since I've been around. I had a question about cycling a new tank, and you folks are pretty much the most knowledgeable ones I know.

I've had a sparsely planted tank set up and cycling with a couple tetras for a little over a month. My water quality tests are coming back... weird.

For the first few weeks I was showing ammonia, and nothing else as expected, but here recently, I'm suddenly showing ammonia and nitrates, but no nitrites. All of my fish-related knowledge tells me that this shouldn't really be possible. I haven't been doing any water changes during this time, just testing the water to make sure it wasn't getting too unbearable during the cycle.

Has anyone ever experienced this? Cause this will be my 6th tank, and I've certainly never seen it. I do have a bit of an algae problem in the tank, almost as soon as we were up and running, brown algae got EVERYWHERE. Could this be part of the problem? And how on earth do I get back on track?

I have to say that cycling with fish isn't that ethical in the fact that if you have too much bioload all the levels can spike and kill or severely harm the fish. Fishless cycles can be a lot more beneficial and you have full control and harm no one.
Also what testing kit do you use?

So as you know your ammonia will go up by a lot. Then nitrite will follow and lastly but not least Nitrate will go up.
And your readings are very possible but that means that your tank was cycled and you haven't been doing enough water changes to remove the excess ammonia from your tank.

I actually got that slightly today. I just got all my girls into their sorority tank and I tested the water today and my ammonia was creeping up so I did a 25% water change to bring it back down. And I've only noticed things like that from dead plants.
What filter are you using? Sponge filters are actually the very best filters. And I don't know if the browning is anything other than things from dead plants that you need to suck up maybe?

I've only cycled 4 tanks so far and have had to often and have only used Sponge filters (except for my friends tank, she had a regular filter).

I know cycling with fish isn't quite ideal. However, I thought that it could be done without much harm to the fish with a big enough tank. The solution to pollution is dilution y'know. This is actually in a 55 gallon tank, so there's some wiggle room for ammonia to creep around before it gets to the fish harming stage. As far as I can tell, it never rose above .25ppm. I'm using a penguin biowheel filter, rated for up to 75 gallons. When everything is established and I get this thing stocked, I'm hoping my betta has the sense not to swim near it. Otherwise it'll just have to go betta-less. :(

As far as water changes, I've never had to do them before to control my ammonia. In my established tanks, my ammonia and nitrites never spike, I only do routine water changes to remove excess nitrates. And my ammonia still isn't extremely high, it's as high as I want to try to grow some bacteria to turn it to nitrites, but... Where are my nitrites!? I can't figure out where the nitrates came from if we're not past the ammonia spike yet... I already tested, the nitrates are not present in my tapwater, so something has to be producing them.

I'm going to assume that I actually DO have nitrifying bacteria in the tank for now, and go with the theory that the algae is choking out my aquarium plants and causing an ammonia spike, unless anyone has any better ideas.